Strobe signals are commonly used to control data transfer in high-speed signaling systems. In a typical arrangement, a transmitting device outputs a data signal onto a data line and simultaneously toggles a strobe signal on a corresponding strobe line to indicate the data transfer. The data and strobe signals propagate together to a recipient device which samples the data signal in response to the strobe signal transition.
For reliable operation, the data and strobe signals should arrive at the recipient device in a relatively precise phase relationship so that strobe-responsive sampling will occur at the desired sampling instant. Phase error between the data and strobe signals resulting from propagation-time differences on the strobe and data lines or from operational variations in the strobe and data signal drivers or receivers may cause the data signal to be sampled at a non-optimal point, reducing signaling margin and increasing the likelihood of bit errors.